In aircraft manufacturing and more specifically fuselage manufacturing, a large number of components must be joined together, generally by the use of bolts or other fasteners inserted through aligned holes of various mating components. For example, multiple cured fuselage skins, frames, and stringers may be joined to form a single 360-degree section of the fuselage. Multiple 360-degree sections may be joined length-wise to form a complete fuselage. Because of the large size of these components, and the tight tolerance requirements of the fuselage, it is common for alignment errors to occur during different steps of assembling the 360-degree fuselage sections.
To account for this, pilot holes (smaller than a diameter of the fasteners or bolts of the fuselage) are generally drilled into the multiple fuselage skins, frames, and stringers. Once these various components are brought together to form the single 360-degree fuselage section, the components are fixed relative to each other via some of the pilot holes before full-sized holes for the fasteners are drilled through overlapping sections of the skins, frames, and stringers. Thus, the pilot holes do not each have to match exactly, since they are replaced with full-sized holes once the parts are all brought together for assembly. Any required trimming of the various fuselage skins, frames, and stringers may also be performed during assembly of the 360-degree fuselage section, as needed.
The drilling of pilot holes followed by the later drilling of full-sized holes is inefficient. However, current determinant assembly technology alone is not precise enough to allow full-sized holes to be drilled into spatially separated individual fuselage parts with enough accuracy to match mating holes within the desired tolerance range during fuselage assembly.
Furthermore, an entire 360-degree fuselage section must generally be assembled before various control systems can be installed therein, because drilling holes within the fuselage skin, frames, and stringers for attachment creates byproduct which can contaminate the control systems. Thus, the fuselage is generally assembled into complete 360-degree fuselage sections, then the byproduct from the drilling of the full-sized holes for the fasteners is washed out, and then the control systems are installed. This requires multiple installers in cramped-quarters to install the control systems inside of the completed fuselage. In particular, the cargo bin between the bottom of the fuselage and the aircraft's floor can be fairly small and provides limited space in which an installer can work.
Accordingly, there is a need for an improved method aircraft assembly that overcomes the limitations of the prior art.